Amid mounting global pressure and a range of lawsuits, Ben Emmerson QC, the UN’s special rapporteur on human rights, argues that the U.S. must open its program of targeted killings to impartial investigation or face a U.N. inquiry.

“We can’t make a decision on whether it is lawful or unlawful if we do not have the data. The recommendation I have made is that users of targeted killing technology should be required to subject themselves, in the case of each and every death, to impartial investigation. If they do not establish a mechanism to do so, it will be my recommendation that the UN should put the mechanisms in place through the Human Rights Council, the General Assembly and the Office of the High Commissioner”, he said.

He continued: “The Obama administration continues formally to adopt the position that it will neither confirm nor deny the existence of the drone program, whilst allowing senior officials to give public justifications of its supposed legality in personal lectures and interviews. In reality the administration is holding its finger in the dam of public accountability. There are now a large number of law suits, in different parts of the world, including in the UK, Pakistan and in the US itself, through which pressure for investigation and accountability is building.”